Miami-Dade flooding to increase as engineers start identifying miles of risky U.S. coast

A new study has found flooding in some parts of Miami-Dade County could experience eight times as much flooding by 2045 as the Corps launches an ambitious plan to assess coastal risks from Florida to North Carolina and Mississippi. Hector GabinoEl Nuevo Herald

A new study has found flooding in some parts of Miami-Dade County could experience eight times as much flooding by 2045 as the Corps launches an ambitious plan to assess coastal risks from Florida to North Carolina and Mississippi. Hector GabinoEl Nuevo Herald

With sea rise projections growing ever grimmer — the latest predicts up to eight times as much flooding around Miami-Dade County by 2045 — the U.S. Army Corps of Engineers has launched an ambitious plan to come up with a comprehensive assessment of risks that could easily run into the billions of dollars.

Covering 10,000 miles of vulnerable shoreline from North Carolina to Mississippi, the study for the first time tries to unify what has so far been a patchwork of sea rise assessments.

You’ll have a common framework.

U.S. Army Corps of Engineers Col. Jason Kirk, commander of the Jacksonville District

“You’ll have a common framework,” that creates an equal playing field in the fierce competition for federal dollars, said Col. Jason Kirk, commander of the Corps’ Jacksonville District, which includes Florida and the Caribbean, two of the most vulnerable regions to seas creeping upward.

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In the most recent study of South Florida sea rise, researchers with the Union of Concerned Scientists used the Corps’ revised 2015 calculations for sea rise and found that far more swaths of Miami-Dade County will flood than under a projection they developed only a year earlier with more conservative estimates. The group focused on five cities — Miami, Miami Beach, Key Biscayne, Hialeah and Coral Gables — and found the number of projected floods rose from 45 a year to 80 with a 10-inch rise in sea levels by 2030.

“We wanted to use projections that we felt better reflected what the county is using and the work coming out,” said Nicole Hernandez Hammer, the group’s Southeast Climate Advocate based in Miami. “The reality is we’re already starting to feel the impacts of sea level rise.”

Figuring out how to prepare South Florida has so far been left mostly to local agencies, the study found. Miami-Dade County formed its first sea rise task force in 2006, followed by a regional compact between Miami-Dade and three neighboring counties including Monroe, Broward and Palm Beach. Miami Beach — which drew global attentionwith ongoing reconstruction and plans to install a series of massive pumps — and Miami are also working on plans. Last year, the South Florida Water Management District reassessed canals, flood gates and other structures and is in the midst of shoring up a major canal, the C-4, along the Tamiami Trail. But so far, the state has no comprehensive plan. And that has led to uneven preparation.

At the municipal level, where the rubber meets the road, some cities are taking action but face serious barriers.

Union of Concerned Scientists

“At the municipal level, where the rubber meets the road, some cities are taking action but face serious barriers,” the UCS report concluded, singling out Opa-locka as an example where low-income communities may struggle to keep up.

“There is a high sense of urgency for initiatives to move forward and address sea level rise from the state and federally,” Hammer said.

The Corps assessment attempts to fill that gap, officials said. The agency had been working to find a better way to address sea rise when Superstorm Sandy struck the east coast in 2012. The massive destruction leveled by the storm prompted an autopsy of the region’s failed infrastructure and led to a number of reforms and massive resiliency projects, including an unprecedented $20 billion storm protection plan from former Mayor Michael Bloomberg.

24,000The miles of road in danger of flooding with sea level rise.

Congress followed with instructions for the Corps to assess risk, which produced a look at the North Atlantic coast. Assessing the South Atlantic, where the Corps reports an estimated 6 million people live in vulnerable areas and property at risk totals more than $616 trillion — including 24,000 miles of roads — will complete the shoreline.

Planning, officials say, can save up to 75 percent of the cost of potential harm. South Florida will also play a crucial part in the overall study because so much work in the region has already been done.

“South Florida is ahead of the curve in understanding sea level rise. But other parts have not done as much work, so we’re hoping to leverage,” those efforts, said Jackie Keiser, chief of the Corps’ Jacksonville Coastal and Navigation section, who’s heading up the study.

The Corps is just now starting to contact local agencies and governments and hopes to have a meeting within the next month or two, Keiser said. The study is expected to take two to three years, she said, and eventually produce the kind of blue print that will help smaller cities and governments with fewer resources as well as give the federal government a master list of which areas need to be addressed first.

While likely to be completed over many years, that list could easily amount to the biggest public works project in history, with work as varied as flood control in Sweetwater or beach restoration in Fort Lauderdale. The plan would also help better coordinate projects. For example, when the Corps dredges a channel, it ends up with mounds of sediment that Keiser said can be used to build up shorelines.

“What we want to do with the South Atlantic is get ahead of a direct strike storm,” Kirk said, referring to Sandy. “This puts projects in our region on equal playing field [for] national investment.”